3results about How to "Avoid impedance" patented technology

The present invention relates to a lithium-supplementing positive electrode material and a preparation method and application thereof. The lithium-supplementing positive electrode material has a core-shell structure, including a lithium-supplementing core, a first rigid coating, an active material layer and a second rigid coating arranged in sequence from the inside to the outside, wherein the first rigid coating and the second rigid coating both contain metal carbides and / or metal nitrides. The present invention improves the structural strength of the lithium-supplementing particles while improving the conductivity of the positive electrode material by wrapping the lithium-supplementing particles inside the positive electrode active material and coating the rigid coating on the surface of the lithium-supplementing particles and the surface of the active material layer. This can not only avoid the influence of the structural collapse of the lithium-supplementing particles after lithium-supplementing on the stability of the battery, but also reduce the contact resistance between the lithium-supplementing agent and the active material and between the positive electrode materials, and enhance the conductivity of the positive electrode active material, so that the lithium-ion battery containing the lithium-supplementing positive electrode material has both high energy density and excellent rate performance and cycle stability.

This invention belongs to the field of batteries, specifically relating to an electrolyte and battery for improving the ultra-low temperature performance of lithium iron phosphate batteries. By adding specific film-forming additives and ultra-low temperature functional additives to the electrolyte, the low-temperature liquid state is maintained through the synergistic effect of fluoroethylene carbonate (FEC), 1-ethyl-3-methylimidazolium difluorophosphate, and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, thereby reducing the electrolyte viscosity. At the same time, it can form a weakly solvated sheath layer with lithium ions, significantly reducing the energy barrier required for lithium ions to desolvate at the negative electrode interface, reducing the SEI interface impedance, thereby promoting lithium ion transport and significantly improving the ultra-low temperature performance of lithium iron phosphate batteries.

The utility model relates to a crimping test device which comprises a base assembly, a turnover assembly and a limiting piece, the base assembly is used for bearing a to-be-tested product, the turnover assembly is rotatably connected to the base assembly so as to cover the base assembly or be opened relative to the base assembly, and the turnover assembly comprises a substrate and a substrate connector; the substrate connector is used for being connected with a connector of a to-be-tested product in a pressing mode so that the substrate and the to-be-tested product can be communicated with each other. The limiting sheet is connected to the substrate, is spaced from the substrate connector, and is used for abutting against a connector of a to-be-tested product when the substrate connector and the connector of the to-be-tested product are mutually crimped, so as to limit the crimping depth of the connector of the to-be-tested product crimped to the substrate connector; therefore, the contact area between the connector of the to-be-tested product and the substrate connector can be reduced, the abrasion between the connector of the to-be-tested product and the substrate connector can be reduced under the condition of repeated plugging, and the service life of the connector of the to-be-tested product or the substrate connector can be prolonged.